The duration of the game shall be two equal periods of 45 minutes, unless otherwise mutually agreed upon, subject to the following:
a. Allowance shall be made in either period for all time lost due to substitution, the transport from the field of injured players, time wasting or any other cause, the amount of which shall be a matter of the discretion of the referee.
b. Time shall be extended to permit the taking of a penalty kick being taken at or after the expiry of the normal period in either half.
The half time interval shall not exceed 15 minutes.
Competition rules shall clearly stipulate the duration of the half time.
The duration of the half time interval may be altered only with the consent of the Referee.